Re: [OMC-Boats] Dwell/tach

From: BC Howk <bchowk@...>
Date: Sat, 12 Sep 2009 09:54:36 -0500 (CDT)
some history for your buick should give you some idea about HP gains and torque (I did not realize the buick nail head and the aluminium rover V8 were related, interesting)

Did a quick search for 4bbl intake does not seem to be an easy item to run across, apparently origional buick 4bbl intakes were aluminium......aftermarket doesnt seem to have much for the 300 and 340 (tons of stuff for the 350 and big block buicks)but if you did some research and hunting I bet you could come up with some good performance enhancements for what you have.

Lee swapped in a small block chevy into his sportsman, take a look at his web site he goes into a lot of detail 

if you went on the road of swapping in a small block chevy (like a 350), well you could just go NUTS with aftermarket performance stuff if you wanted. The only question would be how much HP would the old electric stringer actually take....


On Sep 11, 2009, Justin DeSantis <duc1098desmo@...> wrote:

I hadn't planned on adjusting the timing. Just checking it while I was
poking around in there. Once I get in and look around, I'll let you
know if I have more questions. Good to know about the Buick 340. Any
idea of the horsepower increase if I performed said swap? What about
other GM small blocks?

And while we're talking, let me run a few other things by you. I spoke
with a marine mechanic today, he gave me some info on the stringers,
but it's been so long since he's actually worked on one, I wanted to
make sure he was remembering correctly. Because he said a few things
that are in direct contradiction with the owners manual for my boat.
First, we we're talking about oil. I told him I used type C or Premium
(in OMC speak) fluid in the lower and upper gear case. He told me I
goofed. He said they use Type C in the lower gear case, and high vis
in the upper gear case and tilt motor gear case. When I told him the
manual said to use type C in those, he told me I must have read wrong.
Well I checked, and I was right, they call for type c in all those
places. Should I be using Hi vis? He also said there is oil in the
intermediate that needs to be changed. I can't find any mention of
this in the manual.

One more thing, this guy told me changing out the impeller requires
the outdrive to come off the boat before I remove the lower unit. Said
I'd damage it if I removed it without first removing the outdrive from
the intermediate. Now, I know this guy, and he knows his stuff. But
they stopped working on stringers years ago, so it wouldn't shock me
if he's wrong on some of this. Once I get my service manual, I'l' be
golden, but until then, I'm flying blind. No biggie though, I don't
plan on replacing the impeller until winter. This year, I'm storing
the boat in my mother in laws garage so I can get some projects done
on it over the winter. (Let me tell you, it's going to be a real feat
to get it into her garage. The garage is big enough, but the location
will make it tricky to get a boat in. I'll take pictures of that
Thanks for all the info.

On Sat, Sep 12, 2009 at 12:03 AM, Lee Shuster (lib1) <lib1@...> wrote:
> NO, you're describing a SECONDARY HV INDUCTIVE pickup designed to sense
> pulse firing off No.1 cylinder. I'm not surprised that's what you are more
> familiar with. These induction pickups are also commonly used on timing
> lights as well.
> NOTE: I"M Pretty sure that's NOT what you have with the RAC If it has
> the common red and black alligator clips.
> This RAC tach/dwell PROBABLY hooks up to one of (two) the small threaded
> terminals on the COIL. The coil has THREE CONNECTIONS.
> 1) HV SECONDARY which sends high voltage spark to the center distributor
> terminal. IGNORE
> 2) + IGN (PRIMARY) Voltage from the ballast resistor (small threaded
> terminal) IGNORE
> 3) - (PRIMARY) voltage small lead to distributor and lead to tach (Small
> threaded terminal) HOOK UP THE RED TACH LEAD HERE. Connect the BLACK TACH
> lead to any common ground.
> THERE"S NO Timing "port" like you're used to viewing on motorcycles. Instead
> there will be timing "marks" on the rotating damper which is connected to
> the front crankshaft. There will be a static pointer. Point your timing
> light at the pointer when the engine is running (follow the manual
> instructions to adjust timing). The distributor will mechanically advance
> the timing over 20 degrees as you increase the RPMs up to roughly 2750 to
> 3000 RPM. It's not recommended you alter ign timing, until you checked
> compression, gapped the plugs, checked spark plug HT wire resistance/HV, set
> the points & dwell.
> Have fun. BTW, I researched the Buick V8 faimly a little more. The 300
> shares pretty much everything with the 340 and would be a no-brainer bolt
> in. The 350 Buick shares very little, I'm not sure exhaust manifolds would
> swap over.
> On Sep 11, 2009, at 8:00 PM, Justin DeSantis wrote:
>> Cool, I'm looking forward to hooking it up and comparing it's accuracy
>> to my other 2 tachs. Hopefully it's correct. You just clipping it on
>> to the outside of the plug wire like a modern tach, or does it require
>> some special hook-up procedure. One more question where is the port to
>> inspect timing? (I ordered a service manual. Not here yet.)
>> On Fri, Sep 11, 2009 at 8:47 PM, Lee Shuster <lks@...> wrote:
>>> I've got one of those old-school RAC's too. Pretty common back in the
>>> sixties.
>>> Simple to hook it:
>>> 1) You connect the Red side to the (-) coil primary (same terminal which
>>> has
>>> the lead to your distributor points.
>>> 2) Then the other side is connected to a good engine ground.
>>> Should have a switch to change from 6 to 8 cyl. (4 cyl used 1/2 the 8 cyl
>>> reading).
>>> On Sep 11, 2009, at 5:45 PM, Justin DeSantis wrote:
>>>> Hey gang. I borrowed a dwell meter and tach combo from a friend. I
>>>> can't for the life of me figure out how to use it as a tach though.
>>>> It's an old RAC dwell/tach. all it has is red and black alligator
>>>> clips. Other tachs I've used just go to the spark plug cable, one
>>>> wire. How does this thing hook up for use as a tach? One lead to the
>>>> spark plug, one to the battery negative? I know how to use it as
>>>> dwell, but not as tach. Anyone use one of these old beasts?
>>>> _______________________________________________
>>>> OMC-Boats mailing list
>>>> OMC-Boats@...
>>> _______________________________________________
>>> OMC-Boats mailing list
>>> OMC-Boats@...
>> _______________________________________________
>> OMC-Boats mailing list
>> OMC-Boats@...
> _______________________________________________
> OMC-Boats mailing list
OMC-Boats mailing list
Received on Saturday, 12 September 2009

This archive was generated by hypermail 2.2.0 : Tuesday, 29 July 2014 EDT